Popular antibiotic can raise heart rhythm risk

A recent study published in The New England Journal of Medicine reported that the popular antibiotic azithromycin raised the risk of irregular heart rhythms in some users.

Azithromycin, often sold in a five-day dose known as a Z-Pak, is part of the macrolide class of antibiotics, which also includes erythromycin.

Other antibiotics from this class also pose similar risks for those with heart disease risk factors, said Dr. Deepak Bhatt, an interventional cardiologist and associate professor at Harvard Medical School.

"In patients predisposed to certain types of arrhythmia, avoiding azithromycin may make sense," Bhatt says. "Often there are other antibiotics that can be used instead. Antibiotic selection depends on the type of infection."

The study showed that the heart risks from azithromycin, while real, also are quite rare, about 47 deaths from heart disease for every million courses of treatment. For people who had known heart disease, there were an additional 245 deaths.

At the same time, the study did not find similar heart risks with other antibiotics that treat many conditions as well as azithromycin, specifically amoxicillin, part of the penicillin class, and ciprofloxacin, a type of antibiotic known as a fluoroquinolone.

So if your doctor prescribes azithromycin for you, and you have a heart condition, it's worth asking whether an alternative might be equally effective and safer.